2 files changed, 3 insertions, 1 deletions

diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 6baf9b4f8f..2f081a0a85 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -1211,7 +1211,7 @@ class Logger(Filterer):
             if filename == _srcfile:
                 f = f.f_back
                 continue
-            rv = (filename, f.f_lineno, co.co_name)
+            rv = (co.co_filename, f.f_lineno, co.co_name)
             break
         return rv
 
diff --git a/Misc/NEWS b/Misc/NEWS
index b8bdd9c61c..613afd98b8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -48,6 +48,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #9948: Fixed problem of losing filename case information.
+
 - Issue #9437: Fix building C extensions with non-default LDFLAGS.
 
 - Issue #9759: GzipFile now raises ValueError when an operation is attempted